U.S. Pat. No. 4,449,265 to Hoy illustrates an example of a wheeled automatic swimming pool cleaner. Powering the wheels is an impeller comprising an impeller member and pairs of vanes. Evacuating the impeller causes water within a swimming pool to interact with the vanes, rotating the impeller member. The impeller is reversible, with the impeller member apparently moving laterally when the pool cleaner reaches an edge of a pool to effect the rotation reversal.
U.S. Pat. No. 6,292,970 to Rief, et al., describes a turbine-driven automatic pool cleaner (“APC”). The cleaner includes a turbine housing defining a water-flow chamber in which a rotor is positioned. Also included are a series of vanes pivotally connected to the rotor. Water interacting with the vanes rotates the rotor in one direction (clockwise as illustrated in the Rief patent), with the vanes pivoting when encountering “debris of substantial size” to allow the debris to pass through the housing for collection.
U.S. Patent Application Publication No. 2010/0119358 of Van Der Meijden, et al. discloses fluid-powered devices that may, for example, function as motors for APCs. Versions of the devices include paired paddles, with each paddle of a pair connected to the other paddle of a pair via a shaft. When a first paddle of a pair in a particular manner relative to flowing fluid, the other paddle of the pair is oriented approximately normal to the first paddle.